How can people turn away from the Sunnah when it is clear with evidence?

The questioner : Yes, Salim. (May Allah be pleased with him), O Shaykh, when a matter is in the Sunnah of the Messenger of Allah (peace and blessings be upon him), and he followed it and did it himself, how can people deviate from the Sunnah of the Messenger of Allah (peace and blessings be upon him) and bring in ideas from themselves? Hmm.

The Shaykh : Allah, Glorified and Exalted is He, created and distinguished. What? Is that not so? Some people are deficient in knowledge; they do not have knowledge except from others, or they are deficient in understanding; they have knowledge but do not understand as others do, or Allah, Glorified and Exalted is He, grants some of His servants light by which they are guided, even if their knowledge and understanding are little. But we cannot accuse the well-known scholars, who are known for sincere intention and advice to creation, of being obstinate. We cannot do so even if they contradict the text. Rather, we call upon Allah for their pardon and forgiveness for contradicting the text, and we do not make their statement a proof for the text.